The main reason is the recording dye formulation. If I remember correctly low speed disc have dye created for low power/long exposure to the laser beam where high speed disc have dye formulation for high power/short exposure.
RITEKF01 = Ritek media with Fuji dye (the F part) formulated for 16x recording (the 01 part).
I noticed in FW media support list that some drives support recording to RITEKF02, F03 discs but I’ve never seen one in person. I’m guessing those are disc optimized for 8X or 4X recording based around the same Fuji dye.